This invention relates to a track fastener assembly of the type used to anchor seats or cargo to tracks fitted to the floor of a vehicle. The particular embodiment disclosed herein is of a track fastener assembly for securing an aircraft passenger seating unit to the floor of an aircraft. Therefore, the vehicle referred to throughout this application is an aircraft. It is understood that the invention relates as well to other types of vehicles such as trains, buses, or the like.
Many aircraft require the capability to be differently configured to meet varying cargo and/or passenger-carrying requirements such as the removal or addition of passenger seats and/or cargo. In addition, aircraft also must have the capability to easily and quickly relocate or reposition seats and/or cargo. It is often necessary in aircraft to change the spacing between seats to increase or decrease the passenger density throughout a portion of or the entire aircraft. For example, it may be necessary to change the passenger density of a particular aircraft from its normal first class and coach density to an all-coach configuration such as might be necessary with charter operations. In addition, some aircraft, particularly those operating on late-night schedules, carry both passengers and cargo, the cargo being carried in one or more compartments normally used to carry passengers. Also driving this design is the need of aircraft manufacturers to speed their initial installation time, which is a major consideration on large aircraft with many seats.
To provide this capability, aircraft manufacturers install locking tracks that run fore and aft along the deck of the major compartments of the aircraft. These locking tracks have a slot that runs the entire length of the track along its top side. Enlarged cut-out openings are spaced at regular intervals along the length of the track to receive track fasteners to permit the track fasteners to be positioned along and locked into the track in order to secure passenger seats and/or cargo pallets that are themselves secured to the track fastener. These track fasteners are adjustable within the track, thereby permitting the seats and/or cargo to be repositioned or removed.
The locking tracks and track fasteners are both fabricated from metal materials. Even when tightly locked into place, adjacent metal parts can rattle, causing annoying disturbances within an aircraft cabin environment. In an effort to reduce raffling there may be a tendency to over-tighten the track fastener screws. This can potentially lead to damaged screws, stripped threads and jamming of the fastener that makes later removal difficult. Prior art anti-rattle devices include star-shaped washers that are threaded down onto the front stud shaft of the track fastener to lift the seat slightly off of the track and snug-up the front stud onto the bottom of the track surface. These washers are difficult and time-consuming to install, and require special tools.
The present invention quickly and efficiently locks the track fastener into its proper position, prevents rattling and vibration that causes irritating noise and may loosen the track fitting.